The 60-15 Rule of Carbon Footprints

As long as you focus on the things that matter, like electricity, natural gas, gasoline, flying and food.

Although they might only be a small share of your spending, they’ll probably be a huge chunk of your carbon footprint.

The 60-15 Rule of Carbon Footprints

In business people sometimes talk about the 80-20 rule, that 80% of effects comes from 20% of causes.

It’s an idea that came from the Italian economist Vilfredo Pareto, who once observed that 80% of Italy’s land was owned by 20% of its people, and went on to find a similar ratio occurring in many systems.

In business it might be ‘80% of sales come from 20% of customers’ or in economics that ‘80% of wealth is held by 20% of people’.

For carbon footprints it is more like the 60-15 rule. 60% of emissions comes from 15% of spending. And that spending is on carbon intensive things like electricity, natural gas, gasoline, flying and food.

We can show this, using data from the US in 2011.

In 2011 the average American had a personal footprint of about 18 t CO2e. This is the consumption footprint from the average American’s spending, and doesn’t include the further 5 tonnes that result from government and construction spending.

More than 60% of this footprint arises from spending on electricity, natural gas, gasoline, flying and food, but these things account for just 15% of spending. That is the 60-15 rule.

A minority of things you buy dominate your carbon footprint.

If you want to reduce your carbon footprint then you need to focus on these things.

The five elephants in the room

The reason that electricity, natural gas, gasoline, flying and food dominate the average American’s footprint is that they involve a lot of emissions for each dollar spent on them. That is pretty logical, because much of what is being paid for in each case is fossil fuels.

We can take this idea a step further by asking just how many emissions results from each dollar spent on these things. As we did in last week’s post, we can estimate this ‘carbon intensity of spending’ from US emissions and spending data in 2011.

For each dollar an American spends on electricity or natural gas it results in about 5 kg CO2e of emissions. For gasoline this is about 3 kg CO2e, for flying it is about 2 kg CO2e and for food it is around 1 CO2e. But for products it is only 0.5 CO2e and for services just 0.15 CO2e.

When you consider that the average carbon intensity of spending for the whole US economy is about 0.5 CO2e/$, you can see why these five things are so important. And this is in spite of the fact that carbon intensities of spending for electricity and gasoline have dropped in recent years, due to the fracking boom and rising pump prices.

Shifting away from the big five

Spending money on services instead of electricity, natural gas, gasoline, flying or food is a fast way to slash your footprint.

According to the Bureau of Economic Analysis in 2011 the average American spent about $550 on electricity each year, $170 on natural gas, $1300 on gasoline, $350 on flying and about $2300 on food. They also spent a further $1,800 on ‘food services’ (restaurants), probably a third of which actually goes toward food.

If an average American spent $100 less on any of these things, and instead spent that money on services, it would make a large dent in their footprint.

We can show this using our carbon intensities for spending.

For each $100 an average American spends on services instead of electricity or natural gas they will reduce their carbon footprint by half a tonne. For gasoline that is 275 kg, flying 175 kg and for food 85 kg.

What does that mean in real numbers? To spend $100 more on a gardener, cleaner, accountant or mechanic you’ll have to cut something. For electricity that means finding a way to shave 800 kWh from your bill. For natural gas it’s cutting 80 therms. For gasoline it is 30 gallons, or 750 miles in an average car. For flying that is about 700 miles less, and for food $100 is less than a fifth of what is spent on wasted food each year.

These are just examples. From state to state, and country to country, the effect of any of these actions will vary, electricity in particular. The thing that will remain the same is the essence of the 60-15 rule.

A minority of things you buy dominate your carbon footprint.

If you want to shrink your footprint, they are the best place to start.

“meher engineer at 01:38 AM on 1 July, 2013
Julia Whitty’s “21 Percent of Homes Emit 50 Percent of CO2” by Julia Whitty, is part of a family of rules, of which LIndsay Wolson’s “60-15 rule of carbon footprints” (http://shrinkthatfootprint.com/the-60-15-rule-of-carbon-footprints) is a member. Wolfson, in his own words, traces his rule back to “the economist Vilfredo Parteo, who once observed that 80% of Italy’s land was owned by 20% of its people, and went on to find a similar ratio occurring in many systems. In business it might be ’80% of sales come from 20% of customers’ or in economics that ’80% of wealth is held by 20% of people’”. It might interest you.